Hi,
i do not know what server do you use but if i run simple query on FB3
select
o.*
from
partners p
inner join orders o ON p.partid = o.partid
WHERE
p.country = 'Spain';
on non propagated with data tables, plan is:
PLAN JOIN (O NATURAL, P INDEX (PK_PARTNERS))
but if i fill tables with test data and UPDATE INDEX STATISTICS
i got plan
PLAN JOIN (P INDEX (PARTNERS_IDX1), O INDEX (FK_ORDERS_PARTNERS))
then i suppose your real problem is your index statistics or selectivity of some values in joined fields
regards,
karol Bieniaszewski